Wyniki wyszukiwania - Biblioteka Nauki

1

A rhenium review – from discovery to novel applications

100%

Dobrzańska-Danikiewicz A. D. , Wolany W.

Archives of Materials Science and Engineering

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2016

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tom Vol. 82, nr 2

70--78

EN

Purpose: The article characterises rhenium in terms of its physiochemical properties, most popular methods of manufacturing and key applications. The examples of rhenium at a nanometric scales are also presented, taking into account the latest literature reports in this field. The objective of the article is also to present advanced nanocomposite materials consisting of nanostructured rhenium permanently attached to selected carbon nanomaterials - Single Walled Carbon NanoTubes (SWCNTs), Double Walled Carbon NanoTubes (DWCNTs), Multi Walled Carbon NanoTubes (MWCNTs) and Single Walled Carbon Nanohorns (SWCNHs). Design/methodology/approach: The article delineates various manufacturing methods at a mass and nanometric scale. It also describes a custom fabrication method of carbonrhenium nanocomposites and the results of investigations performed in a transmission electron microscope (TEM) for nanocomposites of the following type: MWCNTs-Re, SWCNTs/DWCNTs-Re, SWCNTs-Re and SWCNHs-Re. Findings: Rhenium has been gaining growing importance in industry for years, and its applications are very diverse, including: heat resistant alloys, anti-corrosive alloys, rhenium and rhenium alloy coatings, elements of electrical equipment, radiotherapy, chemistry and analytical technology and catalysis. Carbon-metallic nanocomposites are currently enjoying strong attention of research institutions. Research limitations/implications: The development and optimisation of fabrication processes of materials containing carbon nanotubes or carbon nanotubes coated with metal nanoparticles, especially rhenium, is a weighty aspect of advanced materials engineering. Practical implications: Newly created nanocomposite materials, developed as a response to the market demand, are interesting, state-of-the-art materials dedicated to various applications, especially as gas or fluid sensors, and as materials possessing catalytic properties. Originality/value: The article describes nanocomposites of the following types: MWCNTsRe, SWCNTs/DWCNTs-Re, SWCNTs-Re, SWCNHs-Re, created as a result of hightemperature reduction of a precursor of rhenium (HReO4 or NH4ReO4) to metallic rhenium. This metal is deposited on carbon nanomaterials as nanoparticles, or inside of them as nanoparticles or nanowires whose size and dispersion are dependent upon the conditions of a technological process.

2

The modern approach to manufacturing of carbon-rhenium nanocomposites

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Dobrzańska-Danikiewicz A. D. , Wolany W.

Journal of Achievements in Materials and Manufacturing Engineering

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2022

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tom Vol. 115, nr 2

57--63

EN

Purpose: The aim of the paper is to present the high-temperature method of producing MWCNTs-Re nanocomposites, the selection of satisfactory production conditions and the presentation of the results of microscopic and spectroscopic studies of nanocomposites produced by this method. Design/methodology/approach: Two methods of manufacturing carbon-rhenium nanocomposites were tested: ineffective chemical synthesis and high-temperature reduction using H2, which was proven successful and allowed the production of nanocomposites with the expected properties. The received nanocomposites were investigated using Transmission Electron Microscope (TEM), and Scanning Electron Microscope (SEM), as well as were subjected to spectroscopic examination. Findings: The article presents three steps of MWCNTs-Re nanocomposites fabrication using the high-temperature method, functionalization, impregnation and reduction. As part of own work, satisfactory conditions for producing those nanocomposites using a materials science and heuristic analysis were selected. Research limitations/implications: The proposed high-temperature method allows to join rhenium nanoparticles with MWCNTs permanently. It is reasonable to test in the future whether the method is also effective for other carbon nanomaterials and/or nanoparticles of other metals. Practical implications: MWCNTs-Re nanocomposites can be used as sensors of gases that are harmful to the environment. It was also confirmed that the MWCNTs-Re_4 nanocomposite has catalytic properties. Originality/value: The paper presents a modern approach to the manufacturing of MWCNTs-Re nanocomposites, which assumes the use of a high-temperature furnace to heat the material in a hydrogen atmosphere.

3

Metoda wytwarzania i struktura nanomateriałów typu CNTs–Re

100%

Dobrzańska-Danikiewicz A. D. , Wolany W.

Inżynieria Materiałowa

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2015

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tom Vol. 36, nr 3

116--119

PL

W ramach wykonanych prac badawczych wytworzono nanorurki węglowe trwale pokryte nanocząsteczkami renu. W eksperymencie zastosowano wielościenne nanorurki węglowe oraz jedno- i dwuścienne nanorurki węglowe zmieszane w proporcji 50:50%. Strukturę nowowytworzonych nanorurek dekorowanych Re zbadano za pomocą transmisyjnego mikroskopu elektronowego (TEM). W celu określenia składu chemicznego uzyskanych materiałów zastosowano spektroskopię z dyspersją energii (EDS). Proces wytwórczy nanorurek dekorowanych Re rozpoczęto od funkcjonalizacji CNTs w procesie utleniania, następnie umieszczono je w ośrodku zawierającym prekursor renu. Mokry materiał węglowy umieszczono w specjalnym holderze. Właściwy proces dekorowania nastąpił w wyniku wysokotemperaturowego procesu redukcji HReO4 w atmosferze wodoru i w osłonie gazu obojętnego — Ar.

EN

Methodology was developed of obtaining carbon nanotubes coated with rhenium nanocristals. The multiwalled carbon nanotubes and Single/Double-Walled Carbon Nanotubes mixed in 50:50% proportion were utilised for the experiment. The structure of newly synthesized CNTs-Re was examined using the transmission electron microscope (TEM). The chemical composition was confirmed with an energy dispersive spectroscope (EDS). A fabrication process was started with functionalization of CNTs, then the nanotubes were filtered and placed in a medium containing rhenium precursors — HReO4. The mixture was gently filtered, wet material was placed in a specially designed heat-resistant vessel and finally subjected to initial heating in the atmosphere of H2 and in the shield of inert gas — Ar.

4

Influence of safety culture on the safety level in chosen enterprise

100%

Wolany W. , Spilka M.

Journal of Achievements in Materials and Manufacturing Engineering

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2011

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tom Vol. 49, nr 2

507--513

EN

Purpose: In this paper was carried out the analysis of influence of safety culture, connected with implementation Occupational Health and Safety Management System, on safety level in chosen enterprise. The organizational practices necessary for the effective formulation and maintenance of high safety culture were characterized. Design/methodology/approach: The concept of health and safety at work legislation was defined and the idea of safety culture was discussed. Moreover, the necessity of continuous improvement according to PN-N-18001 standard was showed. In this paper was talked over the problem of accidents and occupational diseases among coal miners, who work in a huge and rich in dangers area. Findings: According to continuous improvement principles is the necessity of monitoring work conditions, conducting regular audits and organizing training courses, which lead to developing high safety culture. Practical implications: Developing of the safety culture brings some profits as reducing numbers of heavy and fatal accidents, increasing the number of detect occupational diseases. The enterprise, which developing high safety culture can expect from employees greater caution and respect for rules and instructions bench. Originality/value: The article indicated that the coal mines needs effective actions which should be directed on increase supervision in workplaces and reducing threats causing industrial accidents. The essence of safety culture was presented.

5

The influence of the parameters of heat treatment on the mechanical properties of welded joints

100%

Łuczak K. , Wolany W.

Archives of Materials Science and Engineering

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2019

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tom Vol. 95, nr 2

55--66

EN

Purpose: The main goal of the work is to determine the influence of the parameters of stress relief annealing on the mechanical and structural properties of welded joints made of chromium-molybdenum type 10CrMo9-10 steel. Design/methodology/approach: In the study, commercial 10CRMO9-10 steel was used, the Polish equivalent of 10H2M. This is a chromium-molybdenum toughened steel, i.e. after normalization (910-960°C) and high tempering (650-780°C). The materials were subjected to heat treatment, tests of mechanical properties, Charpy impact test, hardness of individual material zones, as well as macro and microscopic observations. Findings: The hardness tests indicated, that materials subjected to a single heat treatment possess the greatest hardness. Materials undergoing several heat treatments, possess hardness on a similar level to materials that have been annealed once, however they are characterized by low reproducibility of results. The most important parameter of heat treatment of the tested steel is heating up to a temperature of 690°C. Due to such heating, optimal mechanical properties are achieved, which results in long and safe exploitation of the produced elements. Research limitations/implications: The processes of heat treatment are very important to achieve optimal strength properties of welded joints. Practical implications: The development of energy worldwide has caused the creation of machines working in higher pressure and temperature ranges. The influence of temperatures decreases the service life of a given element. The adaptation and completion of the appropriate process of heat treatment extends the exploitation time of elements. Originality/value: Determining the mechanical properties of 10H2M steel, dependent on the temperature of heat treatment and heating time. It was concluded that the optimal parameter of heat treatment for the tested materials – is heating at a temperature of 690°C.

6

Nanocomposites consisting of SWCNTs/DWCNTs decorated with Re nanoparticles

100%

Dobrzańska-Danikiewicz A. D. , Wolany W.

Archives of Materials Science and Engineering

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2015

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tom Vol. 74, nr 2

53--57

EN

Purpose: The main aim of this work is to present a method for manufacturing nanocomposite consisting of single and double-walled carbon nanotubes and rhenium nanoparticles. A decoration process was started with functionalization of CNTs, then placed CNTs in a medium containing rhenium precursors, inserted it in quartz vessel and finally heating wet material in the atmosphere of H2 and in the shield of inert gas Ar. Design/methodology/approach: The microscope examinations of single- and double walled carbon nanotubes decorated with Re were carried out with the TEM and STEM mode using an HAADF detector. An energy dispersive spectroscope (EDS) was employed to determine chemical composition of the material. Findings: This paper shows the fabrications of SWCNTs/DWCNTs–Re hybrid nanostructures. The researches has found that rhenium nanocrystals are located in the outer walls and in the core of the carbon nanotubes. Research limitations/implications: The development of CNTs decorated with metal nanoparticles has concerned intensive interest in the last decade because of their outstanding sensing properties. CNTs-based gas sensors are attractive because of their small size, low weight, low power consumption, ultra sensitivity (high and prompt response). Originality/value: Rhenium is a heavy metals, possesses very high melting and boiling point, good electrical and thermal properties, and is used in the developing industries such as space, electrical, petrochemicals, chemicals. Searching for new uses of Re, including as a component of nanocomposites composed of CNTs is purposeful and interesting.

7

Carbon nanotubes synthesis time versus their layer height

80%

Dobrzańska-Danikiewicz A. , Cichocki D. , Łukowiec D. , Wolany W.

Archives of Materials Science and Engineering

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2014

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tom Vol. 69, nr 1

5--11

EN

Purpose: The purpose of the article is to present an approach for the optimisation of a synthesis process of Vertically Aligned Multi-Walled Carbon Nanotubes (VAMWCNTs) with Catalytic-Chemical Vapour Deposition (CCVD) on a silicon substrate. Design/methodology/approach: Scanning and transmission electron microscopy was applied for showing the structure and morphology of the synthesised multi-walled carbon nanotubes. Findings:The article presents and characterises nanostructural carbon materials fabricated with the CCVD method using an Fe catalyst deposited on a silicon substrate. SEM and TEM examinations have confirmed that a vertical layer of a CNTs “forest” growing on a silicon substrate containing a metallic catalyst is obtained and enabled to select optimum time for their growth process. Practical implications: Vertically aligned multi-walled carbon nanotubes can be applied in numerous fields of technology, especially in scanning probes, photovoltaic cells, anisotropic conductive materials, semiconductors, membranes, chemical and biological sensors, field emitters in nanoelectronics and in molecular electronics. Originality/value: An approach is presented of optimising the synthesis time of VAMWCNTs with a metallic catalyst using CCVD with an EasyTube® 2000 device by FirstNano.

8

Microscopic and spectroscopic investigation of carbon nanotubes-rhenium nanocomposites fabricated in different conditions

80%

Dobrzańska-Danikiewicz A. D. , Wolany W. , Gołombek K.

Archives of Civil and Mechanical Engineering

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2017

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tom Vol. 17, no. 4

978--985

EN

The article describes the morphology of carbon-metal nanocomposites consisting of nanostructured rhenium permanently attached to carbon nanomaterials, in the form of single-walled (SWCNTs), double-walled (DWCNTs) or multi-walled carbon nanotubes (MWCNTs). Such nanocomposites are produced as a result of the high-temperature reduction of a rhenium precursor, including HReO4 or NH4ReO4, to metallic rhenium, deposited on the previously functionalised carbon nanomaterials in the form of nanoparticles whose size and dispersion are dependent upon the conditions of a technological process. Microscopic examinations carried out with scanning electron microscopy (SEM) and transmission electron microscopy (TEM) confirmed a differentiated structure of the presented nanocomposites depending on impregnation time in a rhenium precursor, which is one of the manufacturing steps of such materials. It has been demonstrated that longer impregnation time brings favourable results for material homogeneity in the whole volume. Moreover, the Raman spectroscopy results of functionalised carbon nanotubes and carbon nanotubes decorated with rhenium also has been presented.

9

Synteza wielościennych nanorurek węglowych metodą katalityczno-chemicznego osadzania z fazy gazowej

80%

Dobrzańska-Danikiewicz A. , Cichocki D. , Wolany W. , Łukowiec D.

Inżynieria Materiałowa

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2014

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tom Vol. 35, nr 6

477--480

PL

Metoda katalityczno-chemicznego osadzania z fazy gazowej (CCVD) umożliwia syntezę wysokiej jakości wielościennych nanorurek węglowych na masową skalę. Można wyróżnić wiele zmiennych, które wpływają w trakcie syntezy na rodzaj i postać produktu finalnego. Celem artykułu jest wyznaczenie najkorzystniejszych parametrów procesu syntezy wielościennych nanorurek węglowych metodą katalityczno-chemicznego osadzania z fazy gazowej przez odpowiedni dobór temperatury i czasu procesu syntezy oraz prędkości przepływu wodoru. Zmienne te wstępnie wyselekcjonowano jako najistotniej wpływające na postać i jakość wytworzonego nanomateriału węglowego. Do obrazowania struktury i morfologii nowo wytworzonych wielościennych nanorurek węglowych wykorzystano skaningową mikroskopię elektronową i transmisyjną mikroskopię elektronową. Badanie stopnia zdefektowania wytworzonych nanorurek węglowych wykonano metodą spektroskopii ramanowskiej.

EN

Catalytic Chemical Vapor Deposition (CCVD) method allows for the synthesis of high-quality multiwall carbon nanotubes on a mass scale. A number of variables that affect the course of the synthesis of the type and the form of the final product can be distinguished. The purpose of this paper is to present an approach for the optimisation of the synthesis process of multiwall carbon nanotubes by Catalytic Chemical Vapor Deposition by appropriately selecting the temperature and time of the synthesis process and the hydrogen flow rate. These variables are pre-selected as one which the most influencing on the character and quality of the produced carbon nanomaterial. To image the structure and the morphology of the newly formed multiwall carbon nanotubes scanning electron microscopy and transmission electron microscopy have been used. Research purity and the degree of defecting of produced carbon nanotubes were made using Raman spectroscopy.

10

Comparison of the MWCNTs-Rh and MWCNTs-Re Carbon-Metal Nanocomposites Obtained in High-Temperature

80%

Dobrzańska-Danikiewicz A. D. , Łukowiec D. , Cichocki D. , Wolany W.

Archives of Metallurgy and Materials

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2015

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tom Vol. 60, iss. 3A

2053--2060

EN

Carbon-metal nanocomposites consisting of multiwalled carbon nanotubes coated with rhodium or rhenium nanoparticles by the high-temperature method were fabricated during the research undertaken. Multiwalled carbon nanotubes fabricated by Catalytic-Chemical Vapour Deposition (CCVD) were used in the investigations. Multiwalled carbon nanotubes functionalisation in acid or in a mixture of acids was applied to deposit rhodium or rhenium nanoparticles onto the surface of carbon nanotubes, and then the material was placed in a solution being a precursor of metallic nanoparticles. The material prepared was next subjected to high-temperature reduction in the atmosphere of argon and/or hydrogen to deposit rhodium or rhenium nanoparticles onto the surface of multiwalled carbon nanotubes. The investigations performed include, respectively: fabrication of a CNT-NPs (Carbon NanoTube-NanoParticles) nanocomposite material; the characterisation of the material produced including examination of the structure and morphology, and the assessment of rhodium and/or rhenium nanoparticles distribution on the surface of carbon nanotubes. Micro- and spectroscopy techniques were employed to characterise the structure of the nanocomposites obtained.

PL

W ramach wykonanych badań wytworzono węglowo-metalowe nanokompozyty składające się z wielościennych nanorurek węglowych pokrytych nanocząsteczkami rodu lub renu metodą wysokotemperaturową. W badaniach wykorzystano wielościenne nanorurki weglowe wytworzone metodą katalityczno-chemicznego osadzania z fazy gazowej (ang.: Chemical Catalytic Vapor Deposition – CCVD). W celu osadzenia nanocząsteczek rodu lub renu na powierzchni nanorurek węglowych zastosowano funkcjonalizację wielościennych nanorurek węglowych w kwasie lub mieszaninach kwasów, następnie materiał umieszczono w roztworze będącym prekursorem nanocząsteczek metalicznych. Przygotowany materiał poddano następnie redukcji wysokotemperaturowej w atmosferze argonu i/lub wodoru w celu osadzenia nanocząsteczek rodu lub renu na powierzchni wielościennych nanorurek węglowych. Wykonane badania obejmują kolejno: wytworzenie materiału nanokompozytowego typu CNT-NPs (ang.: Carbon NanoTube-NanoParticles), scharakteryzowanie wytworzonego materiału obejmujące badanie jego struktury i morfologii oraz ocenę rozmieszczenia nanocząsteczek rodu i/lub renu na powierzchni nanorurek węglowych. Dla scharakteryzowania struktury otrzymanych nanokompozytów zastosowano techniki mikroi spektroskopowe.

11

Ti6Al4V titanium alloy used as a modern biomimetic material

80%

Dobrzańska-Danikiewicz A. D. , Gaweł T. G. , Wolany W.

Archives of Materials Science and Engineering

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2015

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tom Vol. 76, nr 2

150--156

EN

Purpose: The principal aim of the article is to characterise titanium alloy Ti6Al4V as a biomimetic material. The work presents in particular the application of this alloy in regenerative/aesthetic medicine for implants of craniofacial elements against other its other applications in various branches of industry. The article presents a rapid manufacturing (RM) method of fabrication of elements to be used as implants from Ti6Al4V powder. It was demonstrated that the scaffolds created in Selective Laser Melting (SLM) have strictly defined geometric dimensions of an object and open pores, and the pores are regular and repeat within the whole volume of the object. Design/methodology/approach: Scanning electron microscopy was applied for showing the structure of innovative biomimetic materials made of Ti6Al4V powder. Findings: It was confirmed in SEM examinations that the structure of laser-sintered objects consists, within its entire volume, of regularly occurring pores with strictly specified geometric dimensions. Practical implications: Biomimetic materials can be used in regenerative/aesthetic medicine as implants. The purpose of the scaffolds produced is to enable the growth of soft tissue or bone tissue in craniofacial elements. Originality/value: Biomimetic materials can be used in regenerative/aesthetic medicine as implants. The purpose of the scaffolds produced is to enable the growth of soft tissue or bone tissue in craniofacial elements.

12

Carbon nanotubes manufacturing using the CVD equipment against the background of other methods

80%

Dobrzańska-Danikiewicz A. , Łukowiec D. , Cichocki D. , Wolany W.

Archives of Materials Science and Engineering

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2013

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tom Vol. 64, nr 2

103--109

EN

Purpose: The primary purpose of the article is to present the most popular techniques of manufacturing carbon nanotubes (CNTs). The Chemical Vapour Deposition (CVD) method is described in detail with special focus laid on the universality of such technique and on economic considerations. The outcomes of investigations presenting carbon nanotubes fabricated with the EasyTube® 2000 system are also demonstrated. Design/methodology/approach: Electron microscopy was used for illustrating the structure and morphology of newly manufactured multiwalled carbon nanotubes. Findings: The microscopic examinations conducted with high-resolution transmission electron microscopy have confirmed the homogeneity, high quality and purity of the manufactured carbon nanotubes. Practical implications: Carbon nanotubes are currently valued because of their diverse applications. Depending on the structure, carbon nanotubes may act as conductors or semiconductors and such properties can be utilised in electronics. Other fields of application include optics, medicine, transportation (lightweight and robust constructions). CNTs are also utilised as elements of chemical and biochemical sensors, especially when coated with particles of precious metals (e.g. Pt, Au, Pd). Carbon nanotubes are also used as a reinforcing component in composites. Originality/value: The characterisation of carbon nanotubes fabrication methods with special consideration to the chemical vapour deposition method by means of an EasyTube 2000 device by FirstNano.

13

Microscopic And Spectroscopic Research Of The MWCNTs-Re Nanocomposites

80%

Dobrzańska-Danikiewicz A. D. , Wolany W. , Cichocki D. , Łukowiec D.

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nr 3

14

Microscopic and Spectroscopic Research of the MWCNTs-Re Nanocomposites

80%

Dobrzańska-Danikiewicz A. D. , Wolany W. , Cichocki D. , Łukowiec D.

Archives of Metallurgy and Materials

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2015

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tom Vol. 60, iss. 3A

2047--2051

EN

he combination of TEM research and Raman spectroscopy to characterization of MWNTs-Re nanocomposites gives a new notion about the structure and quality of materials obtained. TEM studies indicate that the functionalization method significantly influences the morphology of obtained MWCNTs-Re nanocomposites. Due to the specific spectrum recorded for the MWCNTs they can be distinguished from other forms of carbon, furthermore comparative analysis of the results at different stages of the manufacturing process confirms the covalent modification of the MWCNTs structure. The D-band intensity compared to the G-band intensity provides valuable information about the quality of the sample, in particular indicates the existence of contamination and/or the presence of structural defects. Preliminary results suggest that the high-temperature manufacturing process of MWCNTs-Re nanocomposite improves the quality of the carbon material intended for the experiment.

PL

Wykorzystanie transmisyjnej mikroskopii elektronowej oraz spektroskopii ramanowskiej, zastosowanych do scharakteryzowania nanokompozytów typu MWCNTs-Re, umożliwia określenie struktury i jakości uzyskanego materiałów. Badania TEM wskazują, że sposób funkcjonalizacji znacząco wpływa na morfologię otrzymanych nanokompozytów typu MWCNTs-Re. Charakterystyczne widmo ramanowskie uzyskane dla nanorurek wielościennych umożliwia ich identyfikację, ponadto analiza porównawcza uzyskanych wyników na różnych etapach procesu wytwórczego potwierdza kowalencyjną modyfikację struktury MWCNTs. Stosunek intensywności pasma D do intensywności pasma G informuje o jakości badanych próbek, w szczególności wskazuje na występowanie ewentualnych zanieczyszczeń i/lub obecność defektów strukturalnych. Wstępne wyniki badań wskazują, że proces wytwarzania nanokompozytu typu MWCNTs-Re z zastosowaniem wysokiej temperatury wpływa na poprawę jakości wyjściowego materiału nanorurkowego.

15

Carbon nanotubes decorating methods

80%

Dobrzańska-Danikiewicz A. , Łukowiec D. , Cichocki D. , Wolany W.

Archives of Materials Science and Engineering

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2013

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tom Vol. 61, nr 2

53--61

EN

Purpose: The work is to present and characterise various methods of depositing carbon nanotubes with nanoparticles of precious metals, and also to present the results of own works concerning carbon nanotubes coated with platinum nanoparticles. Design/methodology/approach: Electron transmission and scanning microscopy has been used for imaging the structure and morphology of the nanocomposites obtained and the distribution of nanoparticles on the surface of carbon nanotubes. Findings: The studies carried out with the HRTEM and SEM techniques have confirmed differences in morphology, homogeneity and density of depositing platinum nanoparticles on the surface of carbon nanotubes and its structure. Research limitations/implications: The studies conducted pertained to the process of decorating carbon nanotubes with platinum nanoparticles. Further works are planned aimed at extending the application scope of the newly developed methodology to include the methods of nanotubes decorating with the nanoparticles of other precious metals (mainly palladium and rhodium). Practical implications: CNTs-NPs (Carbon NanoTube-NanoParticles) composites can be used as the active elements of sensors featuring high sensitivity, fast action, high selectivity and accuracy, in particular in medicine as cholesterol and glucoses sensors; in the automotive industry for the precision monitoring of working parameters in individual engine components; in environmental conservation to examine CO2, NOx, and CH4 concentrations and for checking leak-tightness and detecting hazardous substances in household and industrial gas installations. Originality/value: The comprehensive characterisation of the methods employed for fabricating nanocomposites consisting of carbon nanotubes deposited with Pt, Pd, Rh, Au, Ag nanoparticles with special consideration to the colloidal process.

16

MWCNTs-Pt versus MWCNTs-Re nanocomposites manufacturing method

80%

Dobrzańska-Danikiewicz A. , Łukowiec D. , Wolany W. , Cichocki D.

Archives of Materials Science and Engineering

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2014

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tom Vol. 67, nr 1

5--13

EN

Purpose: The primary aim of the article is to compare fabrication methods and present newly fabricated MWCNTs-NPs nanocomposites whose structural components are carbon nanotubes and platinum and rhenium nanoparticles. Design/methodology/approach: The newly fabricated nanocomposites underwent STEM examinations in the bright and dark to show their structure. Raman spectroscopy examinations were carried out, as well, to confirm changes in the structure of carbon nanotubes subject to the experiments. Findings: It was found based on a comparative analysis of the structure of MWCNTs-Pt and MWCNTs-Re nanocomposites that functionalisation methods and a reduction method of precursors of selected noble elements have a significant effect on the structure and morphology of the compared carbon nanocomposites. Practical implications: Nanocomposites consisting of carbon nanotubes decorated with metal nanoparticles, including Pt and Re, possess special electrical properties and a developed specific area, which makes them particularly suitable as active elements of industrial gas sensors. The materials can also be used as biosensors and catalysts in the future. Originality/value: A comparative analysis of the following author’s methods: (i) fabrication of MWCNTs-Pt nanocomposite, which was given numerous awards at international innovation and invention exhibitions and (ii) fabrication of MWCNTs-Re nanocomposite pending patent protection.

17

Manufacturing and structure of nanocomposites consisting of MWCNTs decorated respectively with Rh, Re and Pt nanocristals

80%

Dobrzańska-Danikiewicz A. D. , Łukowiec D. , Wolany W. , Cichocki D.

Journal of Achievements in Materials and Manufacturing Engineering

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2015

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tom Vol. 72, nr 1

39--44

EN

Purpose: The primary aim of the paper is to compare fabrication methods and present newly fabricated nanocomposites whose structural components are multi-walled carbon nanotubes (MWCNTs) and respectively Rh, Re and Pt nanocrystals. Design/methodology/approach: The newly fabricated nanocomposites underwent Transmission Electron Microscopy (TEM) examinations in the bright to show their structure. Spectroscopy examinations were carried out, as well, to determine chemical composition of the material. Findings: It was found based on a comparative analysis of the structure of selected nanocomposites that functionalisation methods and a reduction method of precursors of selected noble elements have a significant effect on the structure and morphology of the compared carbon nanocomposites. Research limitations/implications: Nanocomposites consisting of carbon nanotubes decorated with metal nanoparticles possess special electrical properties and a developed specific area, which makes them particularly suitable as active elements of industrial gas sensors. The materials can also be used as biosensors and catalysts in the future. Originality/value: The paper presents the results of investigations relating to the synthesis of nanocomposites consisting of multiwalled carbon nanotubes and respectively Rh, Re and Pt nanocrystals and their structure and chemical composition.

18

Various forms of platinum deposited on carbon nanotubes

71%

Dobrzańska-Danikiewicz A. D. , Wolany W. , Łukowiec D. , Cichocki D. , Burda M.

Archives of Materials Science and Engineering

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2015

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tom Vol. 75, nr 2

53--62

EN

Purpose: The main purpose of the article is to present interesting forms of platinum at a nanometric scale. There are multiple fabrication methods of nanoparticles, nanowires and other forms of platinum, and the methods proposed in the article are simple and effective. They employ carbon nanotubes in the form of a so-called forest, manufactured by CVD methods and nanotubes dispergated (in a water or ethylene glycol solution) as templates for deposition of Pt nanoforms. Design/methodology/approach: Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) were applied for showing the structure and morphology of platinum nanoforms deposited on carbon nanotubes, and Energy Dispersive Spectroscopy (EDS) was used for confirming the chemical composition of the analysed structures. Findings: The microscope examinations carried out with scanning electron microscopy have shown that platinum may crystallise by assuming the form of, notably, nanoparticles, nanowires and nanocubes. The structure of carbon nanotubes covered with nanoparticles of Pt at a nanoscale could have been observed by applying high-resolution transmission electron microscopy. Practical implications: Carbon nanotubes decorated with Pt nanoparticles and platinum at a nanometric scale are used as, in particular, an active layer of chemical and biochemical sensors. In addition, excellent catalytic properties of platinum are used in various industrial processes, including chemical, automotive and petroleum industry. Originality/value: Chloroplatinic acid H2PtCl6 is an input substance for producing various forms of platinum. Platinum exhibits unique physiochemical properties at a nanoscale, different than its properties at a macro scale. It was confirmed that the selected fabrication method of platinum nanoforms is effective and simple.

19

MWCNT-Pt nanocomposite as the active element of harmful gas sensors

71%

Dobrzańska-Danikiewicz A. D. , Łukowiec D. , Wolany W. , Procek M. , Sękala A.

Archives of Materials Science and Engineering

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2016

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tom Vol. 81, nr 1

14--21

EN

Purpose: The goal of this paper is presentation of the variations in MWCNTs-Pt nanocomposite resistance which were examined in the presence of hydrogen with a rising concentration of, respectively, 1, 2, 3 and 4% H2 as well as nitrogen dioxide with a rising concentration of, respectively, 20, 100, 200, 400 ppm of NO2. Design/methodology/approach: Variations in electrical conductivity for the MWCNTs-Pt composite placed, alternately, in the atmosphere of gas and in the atmosphere of selected gases, were measured with a measuring station equipped with precision and inert gas reducers, mass flow meters, filtration systems of gas mixture and the studied mixture’s humidity and temperature control. An active layer of the transducer consisted of MWCNTsPt nanocomposite deposited thereon. All the measurements were carried out in the atmosphere of synthetic air (20% of O2 and 80% of N2) at 22.5°C. Findings: It was found based on the results obtained that system resistance is rising as hydrogen concentration is rising in the atmospheric air. The results of analogous examinations of variations in MWCNTs-Pt nanocomposite resistance carried out for a varying concentration of nitrogen dioxide in the atmosphere of synthetic air are opposite, because lowering system resistance was noted along with a heightening concentration of NO2. The best results were achieved for the nanocomposite presented in the article having a 5% mass concentration of platinum and with uniformly dispersed Pt particles on the surface of carbon nanoparticles. Practical implications: The outcomes presented signify the selectiveness of the applied system consisting of carbon nanotubes decorated with platinum nanoparticles. It means that this material can be used as the active element of harmful gas sensors. Originality/value: A carbon-metal MWCNTs-Pt nanocomposite with special electrical properties was fabricated in the course of research works, whose originality is based on the appropriately selected composition and the specific morphology.

20

CVD synthesis of MWCNTs using Fe catalyst

71%

Dobrzańska-Danikiewicz A. D. , Pawlyta M. , Łukowiec D. , Cichocki D. , Wolany W.

Archives of Materials Science and Engineering

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2014

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tom Vol. 65, nr 2

58--65

EN

Purpose: The primary aim of the article is to present the method of chemical vapour deposition (CVD) employed for fabrication of multi-walled carbon nanotubes in the presence of a catalyst. The basic growth mechanisms of carbon nanotubes are described and the nanostructural carbon materials are presented and characterised, obtained using the CVD method and an Fe catalyst deposited on a silicon substrate. Design/methodology/approach: Scanning and transmission electron microscopy was applied for illustrating the structure and morphology of the synthesised multi-walled carbon nanotubes. Findings: The microscopic examinations conducted with scanning electron microscopy and high-resolution transmission electron microscopy have confirmed the achievement of an ordered layer of multi-walled carbon nanotubes on a silicon substrate containing an Fe catalyst. Practical implications: Carbon nanotubes, due to their unique properties, can be applied in various fields of technology, especially in medicine, optics, photovoltaics and electronic engineering. CNTs are also utilised as an active layer of chemical and biochemical sensors, especially when their outer surface is decorated with nanoparticles of precious metals. Carbon nanotubes are also used as a reinforcing phase in nanocomposite materials. Originality/value: The characterisation of the chemical vapour deposition method used for synthesis of multi-walled nanotubes with a metallic catalyst with application of the EasyTube® 2000 device by FirstNano.